Removal of static electricity in fibers, textile materials, and other materials capable of being charged with static electricity



Feb. 14, 1961 A. NAu-TouRoN 2,972,036 REMOVAL OF STA'I'IC ELECTRICITY INFIBERS, TEXTILE MATERIALS, AND OTHER MATERIALS CAPABLE OF BEING CHARGEDWITH STATIC ELECTRICITY 3 Sheets-Sheet 2 Filed July 12, 1955 Feb. 14,1961 A U-TQURQN 2,972,086

REMOVAL OF' STATIC CTRICITY IN FIBERS, TEXTILE MATERIALS, AND OMATERIALS CAPABLE OF BEING CHARGED WITH STATIC ELECTRICITY Filed July12,' 1955 3 Sheets-Sheet 3 United States Patent O REMOVAL OF STATICELECTRICITY IN FIBERS,

TEXTILE MATERIALS, AND OTHER MATE- RIALS CAPABLE OF BEING CHARGED WITHSTATIC ELECTRICITY Albert Nau-Touron, Paris, France, assigner to CentreTechnique Industriel dit Institut Textile de France, Paris, France FiledJuly 12, 1955, Ser. No. 521,588 Claims priority, application France July28, 1954 6 Claims. (Cl. 317-2) This invention relates to the eliminationof static electricity in materials, more particularly in fibers ortextile structures which tend to become charged.

It is known that the individual or combined action of many factors can,by acting upon insulating materials possessing a certain dielectricconstant, create a charge thereon. These factors are very numerous andinclude solid or even gaseous friction or internal stresses within theinsulating materials.

This charging action of the above-mentioned factors will generally occurboth in the textile industry and in the industrial treatment ofcellulose products such as, for example, paper, plastic materials, oreven powders, etc.

It is an object of the present invention to provide means foreliminating these parasitic influences in the case of textiles. But itshould be understood that the present invention is equally applicable toall the abovementioned industries, and more particularly to any industrydealing with a material which may become electrically charged.

Efforts have hitherto been made to eliminate the abovementionedinconveniences by the use of certain processes of electricneutralization which are based on calorific and hygroscopic conditioningof the workshop atmosphere. Unfortunately, such installations aredeterirnental to the health, of the personnel and are unduly bulky andVery costly to install.

According to the invention a stream of gas previously exposed to aradio-active substance is projected on to the material charged withstatic electricity. It has been found that a jet of gas conditioned inthis manner will cause complete and practically instantaneousdisappearance of the parasitic electric charges on the material withwhichit comes into contact.

The present description and the following full description willinitially refer to schematic embodiments of the application of theinvention, then proceed to a description of forms of apparatusincorporating further improvements, and will finally relate to forms ofapparatus particularly applicable to machines which stretch textilethreads and machines which spin the latter.

In the accompanying drawings:

Figure 1 is a schematic View illustrating one Way in which a gas jetaccording to the invention may be produced;

Figure 2 is a similar view of a rnodilication in which the gas jet isdirected from below;

Figure 3 shows a particular construction of the radioactive surface;

Figure 4 shows a particular form of the inlet and spray nozzle for thegas jet;

Figure 5 is a section showing the end of a gas spray nozzle;

Figure 6 is a transverse sectional View of a form of active surface isincreased;

which the delivered gas is produced by mixing two constituents;

Figure 12 shows another similar apparatus having a different nozzle;

Figure 13 shows a form of apparatus according to the invention in whichthe nozzle is detachable;

Figure 14 shows an apparatus similar to that of Figure 13 provided withmeans for producing the gas used by mixing two constituents;

Figure 15 Shows a form of apparatus in which the amount of radio-activematerial in contact with the flow of gas can be varied;

Figure 16 is a modification of Figure 15;

Figure 17 represents an apparatus according to the invention installedin a textile machine to effect removal of electrtic charges;

Figures 17a and 17h are sections, respectively on lines XVIIa-XVIla andXVIIb-XVHb, of Figure 17;

Figure 18 is a sectional elevation of a form of apparatus concerned inparticular with, but not limited to, spinning and twisting machines andby which the thread formed or being formed in these machines isde-electrilied during its passage through the interior of thisdeelectrifying apparatus;

Figure 19 is a side elevation of the apparatus shown in Figure 18;

Figure 20 is a plan view of the apparatus of Figure 18 in one position;and

Figure 21 is a similar view of the apparatus of Figure 20 in a differentposition.

The process according to the invention consists in directing a gas jeton to a radioactive layer and utilizing this jet after its passage overthe radio-active layer. The gas jet has an increased activating power,due both to the particular ionizing a rays originating from the ldecayof the natural or artificial radio-active substances employed, and tothe less strongly ionizing rays.

As shown schematically in Figure l, a bed plate 1 is coated on one ofits Hat sides with a layer 2 of natural or artiiicial radio-activeelements. A stream of gas is blown at a certain angle ce relative to thecoated sur face. The gas stream is applied by means of a rigid orflexible passage 3 and, as indicated at 5, forms with the coated surfacea certain angle The action of the reflected jet 5 on the parasiticelectric charges Varies according to the initial composition, speed,temperature, and like characteristics of the ilow of gas arriving at 4.

While Figure l shows an embodiment in which the jet is directed upwards,Figure 2 shows that the jet may also be directed downwards. Moreover thecoated surface may be at an angle qb with the horizontal.

It should be noted that the case in which a is zero is not excluded. Inthis case all of the surface 2 is exposed to the gas stream which movesin the direction of the arrow 8.

The end 6 of the channel nozzle 3 may be cut ofi at an angle as seen inFigures 1, 2 and 3, or the end of the nozzle may be constructed as shownin Figure 4, in which the square cross section of the nozzle includes arectilinear part parallel to the surface 2. and twO volutes 9 whichserve to produce a whirling effect on the applied jet of gas.

Similarlyr the radio-active layer 2 may, as shown in Figure 3, be formedwith corrugations 7 which prolong the contact between the gas stream andthe radio-active material.

The end of the'nozzle may, as shown -in Figure 5, have a conical portion12 which contains a pointed cone 10 ending in a point or needle 11. Withthis arrangement (Figure a laminar discharge is obtained withoutturbulence and flicker of the gas jet.' Moreover, advantage may be takenof the electrostaticV effect of the point 11. The section of the passage13 of the gas ow decreases towards the point, thus causing an increasein the speed of the gas over the layer 2.

Figures 6` and 7 represent a very similar nozzle, in which, however, thegas ejection orice is spread out laterally over the radio-activesurface. The mouth of the nozzle is thus shaped like a small tongue.This arrangement may also beprovided with Va cone body similar to thatof Figure '5, but having a knife-edge and extending along the mouth 14.As shown in Figure 6 the bed plate 1 has a special shape producingdesirable convection eiects and reducing turbulence in the ow.

The components described above as well as those vdescribed below may bemade either of conductive or of insulating materials. K

The radio-active layer 2 may be applied evenly over the bed plate 1, orits thickness may increase in the direction of the gas flow.

Figures 8 and 9 show arrangements in which a certain quantity ofradio-active materialcovers the inner wall surfaces of the end of thenozzle 3. If desired, a certain number of lateral apertures 16 maybeprovided at the end of the nozzle. According to Figure 9, the end oflthe nozzle 3 has a cap 17 formed with perforations 18,

the profile of which is selected to produce convection eiects andincrease the kinetic energy. Radio-active material is distributed on therear randfront walls 19 and 20 respectively of the cap 17.

It is generally preferable that the layer 2 be very thin to preventabsorption of the mass of these radio-active elements. The bed plate 1in the region of the coating may be ofV any shape, more particularlyflat, concave, convex, and the like.

The angle must be chosen in such manner as to remain, under the law ofmechanics of uids, between the critical values at which the fluidbecomes detached from the coating 2.

If it is desired for the gas stream to be humiditied, this can be doneby the well-known methods of bubbling into water or by a prolongedpassage of the gas jet over the surface of an expanse of liquid. Byreason of a certain probable recombination eiect the air bubbled in thewater loses a large part of its conductibility in the presence ofradium'and the second method may be preferred to that of bubbling. Y

Generally the gas stream or jet may contain in suspension carefully anddeliberately chosen dust and other small particles.

The gas stream may be previously subjected to the actionY of phosphorousanhydride or an aqueous solution of deliquescent salt to increase theionizing power'. A certain mixing of the gas ow with ozone or oxygen maybe provided if desired and in this case a neutralizing sweeping orwiping action with a brush or a cloth, having an effect upon the matterto be de-electried, may be effected by any suitable vmeans and in anyYrelevant plane or direction. K K K KY K' Moreover, when the positiveor'negative polarity of the material to be treated is known, one may, bymeans of a magnetic eld,'deflect according to the polarity the a'. or ,6rays arising fromKthe decay of the radio-active substances. K K K Y u .KY

In this manner, a discriminating selection between a and `rays isobtained.`

Figure 10 shows one embodiment of the apparatus using the above process.A certain number of elements already referred to have been representedby the same reference numerals. The bed plate 1 is supported by an arm21 hinged at 23 to a xed base 22. A collar 24 in which the nozzle 3slides is hinged at 25 to the bed plate carrying arm 21, a set screw 26enables the nozzle to be clamped in the collar 24. Y

The hinge 23 enables the direction of the radio-active jet to beadjusted as desired, While the hinge 25 cooperating with Vthe telescopicmounting of the nozzle 3 enables the distance 25 between the nozzle andthe radio-active surface 2 to be varied.

Figure .11 shows a modification applicable to the apparatus according toFigure 10, in which the gas flow comprises a mixture of two gasesproduced by an injector arrangement. The gas under pressure arrives at26', the conveyed gas arrives at 27 under reduced pressure in thechamber 23. Two valves 29 andv 30 enable the relative supply of the twogases to be controlled.

Finally, as in the case of Figure 10, the supply of gas reaching thenozzle 3 is regulated by the valve 15, while that of the conveyed gas isregulated by the valve 30.

Figure 12 shows a nozzle similar to that of Figure 8 but mounted in acollar as in the apparatus shown in Figures 10 and 11.

In Figure 13 the nozzle 3 and the radio-active layer 2 are arranged in ahalf-closed chamber unit 31 having openings such as indicated at 72(Figures 13, 14, 15, 16) preferably in the proximity of thevradio-active layer 2. The gas jet is directed into detachable spraynozzle 32 having a tubular bore 33. K

Figure 14 shows Kan arrangement similar to that of Figure 13, in whichthe angle a is reduced to zero. The nozzle of the conduit 3 has a mouth3K4 of a width equal `to that of the layer 2, and a gas mixingarrangement similar to that of Figure l1 is shown in the apparatus.

In Figure l5 the flat bed plate is replaced by aY sector 35 covered byan intervening curved bed plate 1. The inclination of the sector 35 maybe externally controlled by means of a shaft 36, to which the sector 35is rigidly attached. and which can turn with respect to the chamber unit31. A cover 37, which is easily removed, permits access to the segment35. This arrangement has the advantage that the quantity of theradio-active matter affected by the gas flow from the nozzle mouth 34can be very conveniently varied.

Figure 16 shows a modification of the construction of Figure 15 in whichthe two constituents of a gaseous 'mixture are introduced at 3 and 33.The second gas,

the supply of which is regulated by a valve 39, arrives in the direction4th and the linal mixture is produced at 41. Y

Figure 17 shows how an apparatus according to the invention may be usedto eliminate static electric charges on libers which are induced bystretching in the course of their treatment in'various types of textilemachines concerned with natural, artificial or synthetic textiles.Consequently the illustrated example of the application to a spinningmachine does not limit the invention to this type of machine.

A sliver 42 passes between the grooved rollers 43 and 44, in front of athread-guide or pigtaiL and it leaves the rollers 43 as a completelyorpartially formed thread 45. The zone in which the apparatus according tothe invention will be arranged to work is at 46, for itis in this zonethat the final rate of stretching reaches a maximum value. This producesinternal rubbing of liber against liber and against metal and also thesliver is already partially electrified by reason of previous rollingoperations. It should be noted that there is also an elec- ,trifyingzone beyond the Contact point 47 of the rollers the width of the thread,is supported by a frame 50 by means of an angle bracket 49 with theinterposition of a frontal rail 51. A tubular rod 52 having a mouthpiece 53 at its upper end, is joined to the base of the blast pipe 48.Suicient tightness is assured by the contact of the rod 52 and the blastpipe 48, due to the elasticity of the sides 54 and of the latter.

All the previously mentioned measures for the formation of the gas jetmay be used in this particular case.

An alternating frontal displacement synchronized with and equal .to thatof the sliver-guide bar, or of the ribbonguide bar or other similarmechanism in other textile machines, may be provided to permit areduction in width of the base ofthe blast pipe and its nozzle.

It is obvious that when a certain number `of these apparatus units aredisposed laterally and the above-described alternating movement is used,one may treat not only slivers or threads but also structures composedof bers or tissues of a certain Width.

An apparatus will now be described which is rather different from thepreceding example, which is especially important for spinning andtwisting machines but is not limited in use |to such machines. In thecase of a spinning machine this apparatus (Figure 18) operates in adifferent zone from that of the preceding case, viz; beyond the line ofcontact 47 with the grooved rollers 43.

The thread 45 which has already been completely or partially formed byytorsion passes through the interior of the apparatus.

Another important feature consists in the fact that the apparatus worksat a reduced pressure and can be put to other supplementary purposes, aswill be described below.

In Figure 18 the reference numeral 56 designates the thread guide orpigtaiL the apparatus itself being placed in front of the thread guide56. A front suction tube 57 acts on all the individual apparatus unitsarranged on the individual spindles of the machine.

Clips 58, suitably distributed along the tube 57 secure the tube on themachine frame 50 or preferably on the front rail 51, while leaving itfree to turn about its axis and move, as in the preceding apparatus andfor the same purpose, forwards and alternatingly in the direction of thearrows 59 (Figure 20). To the right of each thread 45 a suction-operatedblast pipe 60 of, for example, rectangular section, constitutes adelivery tube joined to the tube 57. The gas jet is represented by thearrow and the reference numeral 55, taking into consideration the factthat the kinetic energy of the gas is poduced in this case by a reducedpressure in the tube 5 In the vicinity of the outer end 61 of the blastpipe, the general arrangement described above as adopted for the bedplate and its coating of radio-active material is again provided. At theother end of the injector nozzle a lateral opening 62 permits the easypassage of the strand of thread. A sliding obturator 63 can be locked'in position by means of a set screw 65. In the working position (Figure21), the closing device 63 is moved in the direction of the arrow 64 tocover the lateral part of the opening 62 and to leave only two circularorifices through which the thread 45 passes.

As in the previously described embodiments, .the radioactive jet 55 actsupon the thread 45 as the latter moves in the direction of the arrow 66,and eliminates from it instantaneously all parasitic electrostaticcharges.

An orifice 70 in the suction pipe 57 in the vicinity of the opening 62,constitutes a preliminary suction point. This is important when thethread 45 breaks and a tieing up operation is required. The strand ofbers 67, then loose and free, is drawn in the direction of the arrow 68by the junction 69 of the suction tube 57 with the injector nozzle 60.The orice 70 helps, by means of a slight suction, the guiding andautomatic introduction of the loose strand 67 in the direction of thearrow 68 and across the opening 62, due to the provision of the orifice70, extending at an appropriate angle to the right of eachsuction-operated blast and neutralizing tube 60.

The opening 62 may be replaced at the desired inclination by two opposedcircular orifices joined on one lateral side of the tube by a saw cut.

Preferably grounded, the various arrangements described above by way ofexample assure a soft and supplementary continuous cleaning action onthe ionizing exterior surface of the radio-active layer 2. This preventsdust or iine suspensions of textile in the air from becoming depositedon the radio-active surface and thus interfering with, or evendestroying, the neutralizing action of the said surface.

When the machine is stopped to carry out lifting," removal of the fullbobbins and the insertion of the empty tubes or bobbins on the spindlesmay, if required, be simplified by the removal of the front base portionof the blast pipes 60. This may be done by simply turning the tube 57upwardly in the collars 58 by a sufficient angle. Before the machine isput into operation again, the blast pipes are restored to the workingposition, by simple inverse rotation of the tube 57.

It should be noted that in this application to a spinning machine, thereduced-pressure flow of gas in the tube 57 of the last-describedarrangement may be recovered, wholly or partly, as a flow under pressurefor feeding the tubular rod 52 of the preceding arrangement. Moreover,this last arrangement could, due to its de-electrifying action, form auseful addition to known suction systems for threads by simply adding aneutralizing blast tube, while the number of components and equipmentunits may be retained.

Since the invention has been described above only by way of severalillustrative embodiments, the apparatus described may be altered oradapted to particular conditions without departing from the scope of theinvention. In particular the specific example of applying it to theelimination of charges of static electricity on textiles is entirelyarbitrary and any applications in various spheres based on the sameprinciple are equally covered by the lnvention.

The present invention provides arrangements by means of which aparticularly rapid electric neutralizing action can be obtained. Thelength of time required for deelectriiication is reduced practically toits minimum, whichns. one advantage of substantial importance over theexisting art. Moreover, in the apparatus according to the invention, theaction is adjustable in intensity and extent.

I claim:

1. An apparatus for removing parasitic static electricity .fromdielectric materials which comprises means defining an exposedradio-active surface, a support for said surface, a nozzle forconnection to a source of gas under a pressure greater than atmospheric,said nozzle directing a stream of said gas into intimate contact withsaid exposed surface, means for directing the gas stream afterimpingement upon said radio-active surface into engagement with saiddielectric materials, a hinge connection between said support and saidnozzle, and an inclinable collar in which said nozzle is telescopicallymounted for adjustment of the distance between the end of the nozzle andsaid surface.

2. An apparatus for removing parasitic static electricity fromdielectric materials which comprises means defining an exposedradio-active surface, means for directing a mixture of gases intointimate contact with said exposed surface, said directing meansincluding means for connection to a source of one of said gases under apressure greater than atmospheric and for supplying said one of thegases to form said mixture of gases, an injector arrangement foraspiring the other of said gases, and means for directing the gas streamafter impingement upon said radio-active surface into engagement withsaid dielectric materials.

3. An apparatus for removing parasitic static electricity fromVdielectric materials which comprises means defining anexposed-radio-active surface, a support for said surface, a nozzle forconnection to a source of gas Yunder a pressure greater thanatmospheric, said nozzle directing a stream of gas into intimate contactwith said exposed surface, means for directing the gas stream after`irnpingement upon said radio-active surface into engagement with saiddielectric materials, a hinge connection between said support and saidnozzle and an inclinable ,collar in which said nozzle is telescopicallymounted for adjustment of the distance between the end of the nozrzleand said surface, a sector pivoted under the nozzle :for directing thegas stream with an angle of incidence 'of the gas stream on theradio-active surface adjustable j between 0 and 90, and ,said directingmeans compris- .Y ing a detachable blast pipe which discharges anddirects the radio-active gas stream.

4. An apparatus for removing parasitic static electricity fromdielectric materials which comprises means defining an exposedradio-active surface, a support for said surface, a nozzle forconnection to a source of gas under a pressure greater than atmospheric,said nozzle directing a stream of gas into intimate contact with saidexposed surface, means for directing the gas stream after impingementupon said radio-active surface into engagement with said dielectricmaterials, a hinge connection between said support and said nozzle andan inclinable collar in which said nozzle is telescopically mounted foradjustment of the distance between the end of the nozzle and saidsurface, and means for providing a reduced pressure at a point beyondthe radio-active substance.

5. An apparatus for removing parasitic static electricity fromdielectric materials in a spinning machine having a suction chambercomprising communicating suction openings for`receiving thread elements,meanssfor defining a radio-active surface, means for connection to asource of gas under a pressure greater than atmospheric, said meansdirecting a stream of said gas into lintimate contact with^saidradio-active surface, and means for directing the gas stream afterimpingement upon said radio-active surface into engagement with saiddielectric material, said suction chamber comprising an aperture spaced`from said suction openings for applying a limited forcepupon said threadelements whereby the same are guided into said suction openings.

6. In a multi-spindle textile machine, a plurality of devices forremoving parasitic static electricity from the threads being spun, eachdevice comprising means defining anV exposed radio-active surface, meansfor con nection to a source of gas under a pressure greater thanatmospheric, said means directing a stream of gas into intimate contactwith said exposed surface, and means for directing the gas stream afterimpingement upon said radio-active surface into engagement with saidthreads, said devices being connected to a common suction conduit on oneside of said machine, and said devices being connected to undergo analternating frontal movement relatively to said machine.

